Signaling system



- May 27, 1930. L ND ET AL SIGNALING SYSTEM Filed Sept. 30, 1927 Invehtovnsi Hans Lfind,

Hans Laub,

FY-amz Hint, by W,

Their- Attorney Patented May 27, 1930.

j 7 UNIT, STATS HANS LUND, or nnnmn-sorronnnnne, HANS time, or BERLIN-TEGELAND, Ann

FRANZ mum, on BERLIN-FRIEDENAU, GERMANY, 'ASSIGNORS. TO GENERAL ELEG- rare COMPANY, A conroan'rron on NEW YORK SIGNALING SYSTEM- Application filed September 30, 1927, Seria1 No. 223,223, and in Germany January 5, 1927.

Ourinvention relates to signaling and control systems and more particularly to systems adapted for the transmission of signals from stationary polnts to a moving vehicle. Still 5 more particularly ourinvention relates to systems of the type described inPatent No. 1,699,377 entitled Electric train control,

issued May 8,- 1928, to Hans Lundand I-Ians Iiaub, and which is assigned to the same aslo signee as our present application.

a In the above mentioned copending application a primary electrical circuit is mounted upon a train and a secondary circuit is mounted upon the track and positioned to be in; inductive relation with the primary circuit, and adapted to produce current varia- ;tions therein as the trainpasses over the track. If a variable frequency is impressed upon the primary circuit when the said circuit is in inductive relation with the secondary; circuit both current diminutions below a normal value and current increases above a normal value will occur in the primary circuit dependent upon the frequency, Likewise, if the frequency is maintained constant a similar result may be produced by varyingthe constants of the secondary circuit.

Thepurpose of our invention is to provide means whereby either a current diminution or a current increase in the primary circuit may be utilized for the purpose of operating a desired signal or control device. Still a further purpose of our invention is to provide means including an electron discharge device whereby a device operated responsive 1y to such currentincrease, or diminution,

may be maintained in its operated con- I y M dition.

In carrying our invention into effect we utilize a phenomenon, which is. already known in connection with electron discharge devices, of the so-called'glow tubeitype, that when a potential impressed across, the

" terminals of this discharge device is increased to a certain fairly definite value the device will .suddenlybreak down and current will flow between its electrodes. Hav- ,ing thus been broken down the impressed potential may be reduced to afairly definite lowervalue where the discharge will cease.

Thus, for example, if a 110 volt glow tube is employed it will be found that the device will be caused to glow at a voltage of about above, 90 volts after which it will continue to glow. until this voltage has been reduced to a value of, or below, 80 volts. This higher voltage, at which the device is caused to break down or to permit current to flow, we shall hereafter refer to as the dischargevoltage of the device, and the lower voltage at which the discharge ceases we shallhereafter refer to as the extinction voltage of-the device.

y In accordance with our invention we utilize this phenomenon in connection with the system described in the above mentioned application in a manner such that a more re liable operation of the relay, or signaling device, to be operated is produced, and further in a manner such that after said device has been once operated in response to acurrent impulse, or diminution, inthe primary circuit it will be maintained in its operating condition. I

The novel features which we believe to be characteristic of our invention willbe set forth with particularity V in the appended claims. Our invention itself, however,both

asto its organization and method of operation, together with further objects andad vantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawing in which Fig. 1 represents one embodiment of our. invention and Fig. 2 repiesents a modification thereof.

With reference .to Fig. 1 of the drawing,

PATENT OFFICE in a closed circuit mounted upon the track. The inductance coils 4 and 5 respectively constitute the primary and secondary winding of a transformer, the coil 4 being mounted upon the train and the coil 5 being mounted upon the track and soipositioned as tosbein inductive relation with the coil 4 when "the train passes over the track. The'switch 7 is-adapted .to close the cirqllit ofthe inductance 5 and fiml flnserufijin accordance .with desired sigms, as set forth in the above mentioned application. It will thus be seen that with a certain adjustment of the condeneert and inductance 5 a current increase will be produced. the wimaaywinding of: thecircuit 1, 2, 4 as the train passes over the track,

{heroes with a certain difierent adjustment of the condenser fiand inductance 7 a diminution ofthe current normally flowing in the oimuit1,- 2,-4 will be produced. 8 represents the se ondary-winding of the transformer 3 which is connected throughthe blocking condehsergd'across the terminals of an electron.

discharge device 10. -This device 10 is preferably oif tihe usual glow tube construction comprising a vessel containing an inert gas, such asneonor argon, and havingelectrodes spaced apartinthe vessel in a mannerysuch that current passesfbetween them when :the voltage is sulfieiently'inereased. The construction of these devices is well known in theart and need not be further'setiorth here. -11 comprisesa'source 'ofpotential which is connected througha switch 12 and the actuat-ing coil of -a' relay-13to the opposite terpotential-11 through the switch 12,.space1be- V tween' the anode "and cathode of thedevice 1p, and Windin of therelay 13 back' to the ogppsite side 0 the source 11. The relay 13 will thus.be,caused to operate thereby "to ac tuat e a'ny desired signal'or control apparatus. After the trainhas passed the secondary cirwit and t1 e cunrentof the -primary circuit has'been re uced toits normal value onlythe velt s p th v s i i l vi l pre s "the device 10 hut the device will conv lt sl w an mai ta nth' el y .13 in p a ed. "c di n until ,fliedi charge of the i 0 is e ngu ed tyne-operato 1* it b d ire i ize u ent decrease h h m y 996 n, he prima y cir u a wiepen a es Windi g Afir p djths. trans:

Ting; 8- Likewise, if a greater current normally flows 111 the wlnding 14 than 1n the winding2 a decrease of current in the winding 2 will produce an increase of voltage in the winding 8, whereas an increase-of currentin winding 2 will produce a lesser el'l'ect dependent upon the relative magnitude of the two currents. The value of the current :flowing in winding 14 may be adjusted by inductance 18 which, for-complete compensation, should'be ]USl3 equal to the inductance of the transformer 4, 5.

/ InFig. 2 we have shown a modiiication of our invention in which'the structure l5 serves the purposesofboth the transformer o and the relay 13. This structure comprises a U shapedmagnetic core having wound thereonthe pri1nary2, secondary winding 8 and the compensating winding 14. In this case the alternating current generator 1 supplies I alternating current to the primary circuit constituted by the winding 2 and the coil 4, and also supplies polarizing potential to the discharge device 10 through the secondary windingc8. The compensating.winding 14 is connected directly across the terminals of the generatorl. Pivoted at ,a point intermediatethe openends of'the Ushaped member is an armaturelG which is adapted when the coreis energized to engage the contacts 17 which may be connected in any suitable electricalcircuih Coil15 ispositioned onthe trackin inductive relation with theco'il 4 and current increases, or diminutions, as the .case inay be, will be produced thereby in the primary circuit, thereby energizing the core memberand causing the armature 16 to engage the contacts 11 and the discharge device 10 to break down. The device 10 havi'ng broken down will maintain themagnctic core energized and the armature 16in its actuated position.

lfV'hile we have particularly mentioned the use of the device '10 as a means for retaining the relay, or ot her signalingor control device, in it s operated condition it, of course, will "be apparent that it possesses markcd advantages in t-hat -inresponse to a small changein current the primary circuit a comparatively large current may be vcaused to :fiow through the windings of the signaling device. Likewifimiwhile have particularly mentioned the useof the (glow tube as. a no ally inactive qdevicezwhich. discha ges urrentin respons t a c r n variat on The use of the compensating winding on the transformer produces marked advantages in the operation of the system in that it substantially compensates the eiiect of leak age reactance in the transformer to thereby increase the possible current variations in the primary circuit. Its use also permits of a larger percentage increase in voltage in the secondary winding. If desired two transformers may be employed,one of these being adapted to produce secondary voltage increases in response to a current diminution in the primary circuit, and the other in response to a current increase in said circuit.

Thus it is possible to transmit two signals practically simultaneously, one a main signal and the other an auxiliary signal.

While we have shown and described a par ticular embodiment of our invention it will,

of course, be understood that we do not-wish to be limited thereto, since many modifica tions may be made, both in the circuit arrangement and in the instrumentalities employed without departing from the spirit and scope of our invention as set forth in the appended claims.

What we claim as new and desire to secure by Letters Patent of the United States, is 1. In combination, an electrical circuit, means whereby a current variation is caused therein, means adapted to be operated responsively to said current variation, means for retaming said means 1n1ts operated condition after said variation has passed, said retaining means including a normally inactive electron discharge device and means responsive to said flowing therein when said train passes over i the track, an auxiliary circuit, a transformer having a winding connected in said primary circuit, a winding connected in said auxiliary circuit and a compensating winding, means adapted to be operated in accordance with voltage variations on said secondary winding and means including an electron discharge device for retaining said last means in its operated condition.

3. In a railway signaling system, a primary circuit mounted upon a vehicle and energized from a source of alternating current carried by the vehicle, a secondary normally deenergized circuit positioned upon the track in inductive relation with the primary circuit when the vehicle passes over the track and adapted by the circulating currents induced therein by the primary circuit to vary the current flowing in the primary circuit When the vehicle passes the secondary circuit on the track, means arranged to be operated from one position to a dillerent position in response to said variation, and means including an electron discharge device for retaining said means in said different position independently of said source after the secondary circuit is passed. i a

4. In a train signaling system, a primary circuit mounted upon a train and connected to a source of alternating current, a secondary circuit mounted upon the track and positioned to be in inductive relation to said pri mary circuit and adapted to vary the current flowing therein when said train passes over the track, an auxiliary circuit coupled to said first circuit including an electron discharge device having a certain discharge voltage, a lesser extinction voltage and polarized at a potential intermediate said two voltages said device being adapted to discharge responsively to said current variations, and means adapted to be operated responsively to current flowing through said device resulting from said discharge.

5. In combination, an alternating current circuit, a second circuit adapted for relative movement with respect thereto to produce a current diminution in said first circuit, a transformer having a primary winding, a secondary winding and a compensating winding, said primary winding being connected in saidfirst circuit and so energized with respect to said compensating winding that a current diminution in said primary winding produces a voltage increase in said secondary winding, means adapted tobe operated responsively to said voltage increase and means including an electron discharge device for retaining said means in its operated condition. 7

6. In combination, an electrical circuit, means for producing current variations therein, an electron discharge device, a source of polarizing potential for said discharge device of a certain value, said device being adapted on a certain variation of potential above said value to discharge and, on a certain variation of potential below said value, to extinguish said discharge, means adapted to be operated in response to a discharge in current through said device, and means for impressing a varying potential on said device exceeding one of said certain variations.

7. In combination, an electrical circuit, a core comprising a normally open magnetic circuit, an armature in saidmagnetic circuit adaptedto be actuated in responsetoenergization thereofl a primary windingon said core connected in said electrical circuit,-a secondary winding on said core, means 'for producing current variations in said primary circuit suflicienjt to cause actuation of said armature andmeans for retaining said armature in its-actuated condition; saidmeans including an electrondiseharge device connected -in circuit with said auxiliary winding.

8; In a railway signaling system, a primury circuit mounted upon a vehicle and energized from-a-source'of alternating current, a secondary circuit arranged upon the track and positioned tohein inductive relation with said primary circuit and adapted to vary the current flowing therein when the ve hioles passes over the track, means adapted to be operated from onecondition'to a different condition in response to saidwariation, means including a normally inactive electron discharge device for retaining said last means in said difl'erent condition after said second ary circuit is passed, and means responsive to and variation for'rendering said discharge device active. 7 V

In witness "whereof, we have hereunto set our hands this 6th day of September, 1927. i

HANS LUND. HANS 'LAUB. FRANZ HIRT. 

